1. Field of the Invention
The present invention relates to alleviation of motor control problems. More particularly, the present invention relates to a computerized method of improving motor control in an individual via somatosensory, proprioceptive and/or kinesthetic sensory training.
2. Description of the Related Art
Motor control problems in individuals are rooted in a variety of different causes, including traumatic injury, disease, aging and gradual "occupational" type injury. If the affected individual is motivated enough to participate in a rehabilitative training program, recovery is possible and is highly dependent on the quantity and quality of the training program.
In cases where motor control problems in individuals are caused by traumatic injury to or disease of the muscle(s) and/or related nerve(s), depending on the extent of injury to the nerve(s), such individuals may or may not experience a corresponding loss of sensory ability. Typical causes of injuries include trauma, stroke, aneurysm, and invasive surgery. Examples of diseases include meningitis and cancer. Historically, regardless of whether the motor control problem is accompanied by a loss of sensory ability, these individuals have been treated with strengthening, flexibility, conditioning and motor retraining techniques, with limited success.
Often, motor control problems are not caused by injury or disease, but are associated with a gradual degradation of motor control over time. Examples include work-induced focal dystonia, Alzheimer, torticollis, cerebral palsy, multiple sclerosis and movement disorders in Parkinson's Disease, Huntington's Chorea, and in other progressive neurological illnesses.
A common origin of focal dystonia is as a component of a repetitive strain injury (RSI) which appears to be the result of attended rapid movements repeated over a relatively long period of time. Generally, these potentially harmful rapid movements occur at a frequency at or below about 100 milliseconds. Typical symptoms of RSI include loss of motor control and involuntary movements of the affected hand, foot, limb or neck of the affected individual.
One example of rapid movements involves musicians and typists, or other skilled manual workers who are required to repeatedly execute rapid alternating movements, e.g., to produce trills and keyboard strokes, to perform a particular assembly line task, etc . . . When executed repeatedly over a period of time, these rapidly alternating movements put one at risk for RSI.
In a study involving musicians with focal hand dystonia, subjects shared common histories of increased practice and of extended, demanding performances under stressful conditions prior to the onset of the disabling symptoms. While most of their biomechanical tests were normal, there was a clear asymmetry in passive finger spread in the central digits, forearm and shoulder rotation. These motor control limitations forced some of the musicians to adopt compensatory awkward end range postures which in some cases caused inflammatory problems of the capsule, ligaments, tendons and fascia, i.e., typical RSI symptoms.
Potentially harmful rapid movements also include rapid simultaneous movement of adjacent portions of a limb which can otherwise be controlled independently, e.g., when multiple digits of one hand, are opened and closed rapidly. In one study involving primates, attended repetitive activities, under the conditions of high cognitive drive were conducted over a three month period.
In one experiment, the monkeys placed a hand on two bars that passively spread apart within 20 milliseconds. The monkeys were required to squeeze the palm and the digits against a hand piece while maintaining close contact with the hand piece during the entire movement trial. The hand piece opened between one and seven times per trial for a total of 1300 repetitions in a training session. In a second experiment, the monkeys were required to repetitively squeeze the hand piece. A successful trial required full hand contact, 80 grams of force, squeezed for 500-1000 milliseconds. Each successful trial was rewarded, with approximately 400 trials completed per training session.
Following about eight weeks of training, despite continued rewards, these monkeys began to avoid training. For example, they began to decrease the time and repetitions of the sessions and would lick their thumbs or hand as if it was painful. They also developed some compensatory strategies such as reducing the intensity of the grasp on the hand piece and/or using an arm pulling instead of the required hand squeezing strategy. When training was continued, symptoms of an occupationally induced RSI emerged in all five subject monkeys after approximately five weeks. Four of the five monkeys showed signs of inefficient motor control of the required tasks as well as in other non-trial movements such as retrieving food. The fifth monkey developed the most serious dystonic movements in the fourth digit of the trained hand.
Hence, it appears that subjects who suffer from RSI can develop a form of focal dystonia, a disorder of motor control manifested in a specific context during rapid skilled, attended movements. Unlike traumatic injury patients, most RSI subjects experience a slow onset of symptoms, often beginning as a feeling of awkwardness, fatigue, or impaired timing or force. Eventually, if the potentially harmful repetitive movements are continued, the degradation of motor control is often preceded, paralleled or followed by painful inflammatory problems of the capsule, ligaments, tendons and fascia.
Conventional RSI treatment such as strengthening, flexibility, conditioning and motor retraining exercises appear to offer only temporary relief. This is because the conventional treatments are directed at the symptoms and but do not attempt to identify nor address the source of the problem. As a result, despite rest and conventional treatment, the motor control problems and any accompanying inflammation often return as soon as the subjects attempt to resume the repetitive movements.
In view of the foregoing, there are desired improved techniques for addressing motor control problems accompanied by sensory degradation using a training regimen that addresses the root of the motor control problem and not just the symptoms of motor control. Such a regimen should offer a comprehensive solution thereby enabling the affected individuals to substantially regain normal motor control over the longer term.